A radial compressor and a method of the type mentioned above are known from WO 2005/045201 A1.
For purposes of guiding flow, single-stage and multistage radial compressors in which one or more compressor impellers are arranged on a compressor shaft in a compressor housing of the respective radial compressor have stator component parts which surround the compressor impellers of the respective radial compressor and which are arranged in layers or one behind the other in an axial direction of the radial compressor and together form a stator assembly of the radial compressor.
The last stator component part of every stage contains a fluid passage which collects the fluid to be compressed and supplies it to a discharge nozzle through which the fluid exits the compressor housing and is supplied to a subsequent process. This fluid passage, which accordingly serves to guide out fluid that is accelerated by the last compressor impeller, can be constructed as a collector space or as a spiral space.
Spiral space refers to a space which develops or increases in cross section over the circumference of the radial compressor and final stator part, respectively, and into which the fluid or medium which is, e.g., gaseous or liquid is introduced via a diffuser and then guided out of the compressor housing at a greatest cross section of the spiral space. In contrast, collector space refers to a space having a constant cross section over the circumference of the radial compressor and final stator part, respectively, and the fluid which is, e.g., gaseous or liquid is guided into the space via the diffuser and guided out of the compressor housing at any location or at a desired location.
FIG. 1 shows a schematic view of a construction of a radial compressor 1′ corresponding to the prior art using the example of a single-stage barrel compressor.
According to FIG. 1, gaseous fluid, for example, is guided into a compressor impeller 13′ rotating along with a compressor shaft 20′ in a compressor housing 10′ of the radial compressor 1′ via a fluid inlet 12′ formed by the compressor housing 10′ and an inlet insert 11′ and is conveyed out of the compressor impeller 13′ radially into a diffuser passage 16′ which is limited by an inner part 14′ and a spiral/collector space body 15′ and which guides the fluid into a spiral/collector passage 15a′ (a fluid passage for guiding out fluid that is accelerated by the last compressor impeller) which is formed in the spiral/collector space body 15′. The fluid is guided to a fluid outlet 17′ of the compressor housing 10′ via the spiral/collector passage 15a′ and is supplied to a subsequent process.
A collector space body or spiral space body of this kind which has a collector passage or spiral passage and which forms a fluid discharge element of a radial compressor is commonly produced as a casting, the collector passage or spiral passage being generated, e.g., by casting cores. However, castings have drawbacks with regard to their lengthy delivery times and the models required for manufacture, which in many cases cannot be reused and which add substantially to production costs for the castings, and with respect to the quality thereof which may vary.
Variations in quality particularly affect dimensional stability (in this case, the dimensional stability of the collector passage or spiral passage in particular) and material structure which, in the case of castings, can be impaired particularly by casting defects. Casting defects can in turn lead to cracks and to machining problems or can even make it necessary to scrap the entire casting.
As a result, radial compressors which are outfitted with conventional fluid discharge elements of this kind are problematic for manufacturers of this type of compressor as far as maintaining the required operating characteristics such as operational reliability or fail-safety and meeting agreed-upon delivery times. Accordingly, the production of radial compressors of this kind can entail high cost risks for the producer which manifest themselves, e.g., in contract penalties, increased procurement costs and/or transportation costs, and so on. Moreover, conventional radial compressors of this type are problematic with respect to standardization and thus with respect to cost optimization of the production process.
It is an object of the present invention to provide a radial compressor of the type mentioned above which has improved operating characteristics over conventional radial compressors and which can be produced with fewer cost risks. It is a further object of the invention to provide a process for the production of a radial compressor of this kind.